Removable plunger arrangement



Jan. 14, 1958 M. c. LUTERICK 2,819,934

REMOVABLE PLUNGER ARRANGEMENT Filed April 5. 1954 .44 I as MARCELLUS C- LUTER/C/(y IN VEN TOR.

HUE BNER, BEE/1'1. ER,

WORREL 8 HERZIG! ATTORNEYS- BYZJWT W United States Patent REMOVABLE PLUNGER ARRANGEMENT Marcellus C. Luterick, Montrose, Califl, assignor, by mesne assignments, Jto Diced Cream of America Co., Los Angeles,'Calif.,.a corporation ofDelaware Application April 5, 1954, SerialNo. 421,057

3 Claims. (Cl. 3092) Thisinvention relates to plunger mechanisms, and:more particularly such mechanisms as are used for dispensing measured quantities of allowable food product,:such.as ice :creamin liquid or semi-liquid form.

Although clearly notlimited to such application, this invention has particular utility in connection 'with ice cream dispensing apparatus of the'type disclosed in U. S. patent application Serial No. 190,202, filed October 14, 1950, for Ice Cream Packaging Machine, :now United States'Patent No. 2,679,966.

it is an object of this invention to provide an arrangetmentof-food dispensing parts which is easily-disassembled for cleaning.

-Itis another object of this invention to provide food dispensing apparatus which does not=involve inaccessible crevices that are virtually impossible to clean.

It is a further object of this invention to providermeans .for facilitating the rapid-disassembly and assembly of :food

dispensing machinery, when the same is required to be cleaned.

It :is a :further object of this invention %to provide :an improved ice cream dispensing pistonand cylinderarrangement which produces an ice cream product of-uniform constituency.

It is another object to provide a means to prevent {injury :to critical parts of dispensing machinery during the cleaning operation.

:Inaccordance with these objects and other objects which will become apparent hereinafter, a preferred embodiment 0f thepresent invention is illustrated in the accompanying drawing wherein:

Figure 1 is a sectional elevation of the apparatus of this invention; and

Figure 2 is a similar sectional elevation showing the .parts in different position.

In Figure 1 there is shown a dispensing cylinder and .piston arrangement generally similar to the dispensingar- Jrangement illustrated particularly in Figure .19 .of the above mentioned UQS. patent'butimproved in.accor'dance withthe present invention.

"The dispensing cylinder and piston arrangement illustrated in Figure 1 comprises a cylinder 11 within which reciprocates a piston 12. The .upper end wall of the acylinderll is comprised of aplate ,13 havingan opening 14 therein. Disposed within the opening 14 is a bushing 16. Loosely fitting and reciprocating in the bushing 16 is a piston rod 17 extending through the bushing 16. The lower end of the rod 17 is secured to the piston 12. It is preferred to form the rod 17 and the piston 12 integrally of a single piece of a polyamide resin such as nylon. Between the rod 17 and piston 12 there is formed, in the integral structure, a shoulder 18 which serves as an upper limit stop for the piston.

The plate 13 may be a circular plate forming part of a turret rotatable about a vertical axis parallel to and spaced from the piston 17, as shown in Figure 19 of said Patent 2,679,966 to which reference is made for a further understanding of this structure. The turret structure also 2,819,934 Ratented Jan. 14, 1958 includes a concentric ring 22, together with several cylinders 11 extending between plate 13 and ring 22. The turret is removably linked to a driving hub 21 by means of several keys 20 'formed on the 'ring 22. As the turret, consisting of plate 13, ring 22 and cylinders 11, is retated about its axis, the ring .22 slides'annularly in-a circular groove 23 formedin a stationary base 24,,c0ncentric with the turret and hub 21.

The interior of the cylinder 11 communicates at {its lower :end with a circular bore 26 in the ring 22, which in turn communicates (when the turret vis properly positioned) with a circular dispensing bore 27 in the base 24.

.At its lower end the bushing 16,is :PIOVldQd with ,an integral flange 28, located inside the cylinder 1 which abuts the inside of the end ;p1ate,13.circumjacent the =opening 14. The bushing16 is held in -place in the end plate or wall 13 by being provided with a peripheral groove 29, the bottom edge of which is substantially iflush with the ,top surface of the,plate,13,; and in the g 20ove29 is seated an elastic, easily-stretchable, :unbroken ring such as aaneoprene 0 ring 31. The outer diameter of the -.0 yring 3.1 is appreciably larger than the opening -14,thereby:pr eventing the bushing 16 from dropping down into :the cylinder 11. When it is desired to remove the bushing 16 from the assembly, it is only necessary to slide or roll the O ring 31 out of the-groove 29 and up the surface of the :bushing and remove it, thereby allowing the bushing todrop throughthe opening 14.

The piston 12 has a resilient ring, .as for example a neoprene -O ring 32, seatedzin agroove therein in close slidingengagement with the inside of the cylinder 11.

In operation the piston :12 measures a charge ,of flowable food, such as ice cream injected into the cylinder 11, when the cylinder is positioned by properpositioning .of the turretover a-feeding opening. The icecreamds-injected .at the bottom of the cylinder 11 under va predetermined pressure, thereby causing the piston '12 to be pushed upward until the shoulder .18 engages the flange 28 of the bushing .16, ,as shown in Figure :1. Thecylinder 11 is thus filled with acharge of icecream.

The turret is then rotated, with the ring 22 riding in the groove 23 untilborei26-isregistered with a dispensing bore 27. Thereupon an actuating arm ,37'is moved-downwardagainst the upperend .of the piston rod 17, causing .the piston 1-2 to discharge the contents-of the cylinder 11 out through the opening 27. Following discharge, the turret is again rotated so that the cylinder may -;b.e refilled with another charge. For further understanding of the dispensing operation above described, reference is madeto the above mentioned patent.

From the brief discription set forth above, it .will :be :readily apparent that the apparatus :herein describedand shown inFigure 1,.0perating as it .does inanenvironment of liquid food product, will require periodicthorough cleaning in;order to meet sanitationrequirements. :In fact, IClfiflDlllgylSIfiQllllfid so often thatit-is most desirable that the parts which are subject to contact ;by the food [be "readily disassembled so that :they can ;be zthoroughly sterilized and cleaned before beinggreplaced. In :accordance with the present invention, the parts are so made that all surfaces which might become contaminated with the food product, are readily exposed and removed from the machine for quick cleaning.

This cleaning operation is effected by the removal of the turret from the rest of the mechanism including the base 24 and hub 21. Such removal exposes the ring 22 to accessibility for cleaning. The piston 12 including the rod 17 should also be readily removable for cleaning. It is desirable, however, that in the disassembly and assembly operations the piston 12 be held up in the cylinder 11 so that it does not drop clear of the ring 22 to a posi- 3 tion where it might be injured or nicked, when the turret is lifted from the base 24. It is further desirable that a safety means should be provided so that the piston does not drop completely out of the cylinder 11 in case of forgetfulness of the operator. To these ends the rod 17 is provided with two axially spaced grooves 33 and 34 in which is selectively disposed an elastic, easily stretchable, unbroken ring, as for example, a neoprene ring 36.

In normal operation the ring 36 is seated in the upper groove 34. This allows the piston 12 to reciprocate to its normal excursion without interfering in any way with the operation of the apparatus. At the same time it serves as a safety measure to prevent the piston 12 from dropping completely out of the turret during the removal operation. In practice it is desired that the piston 12 should be suspended up in the cylinder 11 so as to prevent damage to the piston. During the removal operation, therefore, the ring 36 is slid or rolled out of the groove 34 and shown into the groove 33, as shown in Figure 2. Thus the piston 12 is held in the turret and is not allowed to drop clear of the ring 22 Where it might become damaged as by nicking.

The arrangement described and illustrated is particularly eiiicacious in providing quick and ready disassembly and assembly of the parts during the periodic cleaning and sterilization which must be made at regular intervals, as will be evidenced from the following description of the operation. 7

To clean the apparatus the operator first lifts the piston rod 17 and then rolls the 9 ring 36 down from the groove 34 into the groove 33. He then allows the rod 17 to drop to the position shown in Figure 2, wherein the piston 12 is held up in a safe position. The turret, including plate 13, ring 22 and cylinders 11, is then lifted from the base 24 and from hub 21. During this removal operation the piston 12 is held up out of harms way by the 0 ring 36.

The operator then removes the O ring 36 completely from the piston rod 17 and allows the piston and rod to drop completely out of cylinder 11. The piston 12 and rod 17, being made of a single integral piece of nylon, and being formed without small crevices, is then readily cleaned and sterilized.

Since the crevices around the bushing 16 must also be cleaned, it is a simple matter to remove the bushing from the turret simply by rolling up the O ring 31 and allowing the bushing 16 to drop down clear of the cylinder 11. The bushing 16 may then also be cleaned.

It will be noted that the O ring 32 is also readily removable from the piston 12 for sterilization of the groove in which it is seated. The parts are replaced in the reverse order and the machine is ready for opeartion.

The upper groove 34 not only allows the O ring 36 to provide a safety feature precluding accidental dropping of the piston out of the cylinder 11, but also provides 2 a convenient repository for the 0 ring 36 during normal operation when it is not needed for the retention feature illustrated in Figure 2.

The fact that the piston 12 and associated rod 17 are made of nylon is important, because this material is not only sanitary in that it will not corrode from the constant contact of food, i. e., the ice cream, but it is also very light in weight. This light weight feature is important in the commercial dispensing of ice cream, because a heavy piston and rod would cause the ice cream to become compressed as it is forced into the cylinder by the pressure behind it. This compression of the ice cream would force out some of the air content in the ice cream, thus renderit more dense with consequent loss of profit to the ice cream manufacturer, as well as making a non-uniform, heavy product which is not as saleable. Thus the light weight of the piston and rod markedly contributes to a uniform ice cream product of relatively low density. In a highly competitive market, where density of the ice cream is quite critical, this factor is quite important.

From the above description it will be seen that there has been provided by this invention an arrangement of parts whereby the reciprocable piston and associated elements may be quickly and easily disassembled for cleaning, and in which the resulting product may be maintained at uniform density without the undesirable expulsion of air.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is to be accorded the full scope of the claims.

I claim:

1. Dispensing apparatus comprising a cylinder having an opening in at least one end wall thereof, a piston re ciprocable within said cylinder, a piston rod secured to said piston and extending through said opening, a bushing circumjacent said rod and disposed in said opening, said piston rod being fitted and reciprocating loosely in said bushing, said bushing having a flange on the inner end thereof abutting the Wall of said cylinder around said opening, said bushing also having a peripheral groove therearound immediately outside said wall, and an elastic, easily stretchable, unbroken ring disposed in said groove, the outer diameter of said ring being greater than the diameter of said wall opening, said ring thereby holding said bushing in position in said Wall.

2. Apparatus according to claim 1, wherein said rod is provided with a pair of spaced circular grooves therearound, and a resilient ring selectively disposable in either of said grooves, the outer diameter of said ring being larger than the inner diameter of said bushing, whereby said ring constitutes an adjustable limit stop restricting inward movement of said rod into said cylinder.

3. Apparatus according to claim 1 wherein said piston and rod are formed integrally of one piece of nylon.

References Cited in the file of this patent UNITED STATES PATENTS 277,213 Bunkerhofi May 8, 1883 1,637,247 Snyder July 26, 1927 1,932,796 McNaught Oct. 31, 1933 1,933,371 Eastman Oct. 31, 1933 2,055,602 Dodge Sept. 29, 1936 2,128,254 Kile Aug. 30, 1938 2,354,649 Bruckner Aug. 1, 1944 FOREIGN PATENTS 116,079 Great Britain Aug. 8, 1918 

